The prior art already includes apparatus and method for positioning sheets in a stream of overlapped or shingled sheets which are moved to a collection point where the shingled sheets are formed into a stack of sheets. At that point, the sheets are sometimes manually lifted to another location, and the sheets are sometimes strapped into discrete stacks and end boards and metal strapping may be used for containing the sheets in the stack. In those prior art examples, manual handling is required and/or strapping and end boards are required, and thus the prior art requires labor and the materials mentioned, both of which are eliminated in the present invention.
The present invention provides for both apparatus and a method for fully automating the movement of sheets between a printing press and a sheet bindery, such that no manual handling is required and there is no requirement for special sheet stacking and tying materials. In accomplishing this objective, the present invention provides apparatus and method for receiving a stack of sheets on a tray or the like and lifting and moving the stack of sheets by an automated mechanism, such as a robot, to a position adjacent the sheet bindery of the conventional nature, and from there the sheets are again maneuvered by automatic equipment, such as a robot, and the tray with the stack of sheets thereon is lifted into the sheet bindery at which point the sheets are ejected from the tray and the tray is placed back into a magazine or the like and is available for re-use.
A further aspect of this invention is to provide a sheet quantity detecting mechanism in the sheet bindery, such as a sensor which will detect the height of the stack of sheets in the sheet bindery, and the sensor can be operatively related to the robot feeding the sheet bindery, so that the robot will operate to pick up a new stack of sheets on its tray and position that in the sheet bindery, all as required by the sensor effective with that sheet bindery.
Accordingly, the present invention provides apparatus and a method for automatically positioning a stack of sheets which is on a tray and to control the stack without requiring end boards and strapping of the stack in the conventional manner, but the present invention nevertheless does provide compression for the stack of sheets and physical control of the stack and its tray but without the requirement of tying and ultimately untying the stack of sheets.